Radiation source



FIG. 1 is a perspective view of a radiation source embodying the new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a side view thereof;

FIG. 6 is another side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines illustrate portions of the mammography machine that form no part of the claimed design. 

CLAIM The ornamental design for a radiation source, as shown and described. 